"But they have better education about health issues. They will also have the money to buy lower-fat or organic foods."

He said cheaper healthy foods needed to be made more widely available to the less well-off.

"If they are going to buy a loaf of bread, they may well have to choose the cheapest - and that is likely to be a large white loaf, rather than a brown organic one."

He added: "These are white working class people living in areas of council flats where diet is poor and exercise isn't taken regularly.

"Findings apply across the age scale. You are talking about whole families who are overweight. There are low levels of education about diet.

"They are fairly old-fashioned communities, with more chip shops than Thai restaurants, for example."

'More gyms'

He said people in towns such as Kingston upon Thames were more educated and had more cosmopolitan tastes.

"They travel more, read different newspapers where health sections encourage them to try different diets and exercise.

"There are more gyms and they have money to join. Perhaps businesses are more willing to look after employees' health."

Dr Nick Summerton, a GP in Hull and head of the division of public health and primary care at the University of Hull, has been asked by local primary care trusts to suggest a way to tackle the problem of heart disease in the city.

He told BBC News Online: "Sometimes through no fault of their own some people are unable to loose weight, stop smoking or take more exercise.

"Within Hull we are trying to move away from the old fashioned and simplistic blame culture towards a postion where we assess patients overall risk of heart disease and then tailor the approach to them.